feat(dross): settings endpoint (avatar/accent/persona/voiceMode)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/api/routes/dross.js

@@ -0,0 +1,23 @@
+import { Router } from 'express';
+import { z } from 'zod';
+import { validate } from '../validate.js';
+import { asyncWrap } from '../errors.js';
+import { requireOwner } from '../cap.js';
+import * as settings from '../../db/repos/app_settings.js';
+
+const DEFAULT_SETTINGS = { avatar: 'soft-eye', accent: '#a86adf', persona: '', voiceMode: 'review' };
+
+export const router = Router();
+
+async function getCfg() { return { ...DEFAULT_SETTINGS, ...(await settings.get('dross', {})) }; }
+
+router.get('/settings', asyncWrap(async (_req, res) => res.json(await getCfg())));
+
+const settingsBody = z.object({
+  avatar: z.enum(['soft-eye', 'wisp', 'motes']),
+  accent: z.string().regex(/^#[0-9a-fA-F]{6}$/),
+  persona: z.string().max(8000),
+  voiceMode: z.enum(['review', 'handsfree', 'action'])
+});
+router.put('/settings', requireOwner, validate({ body: settingsBody }),
+  asyncWrap(async (req, res) => res.json(await settings.set('dross', req.body))));